Eigen
3.3.9

Base class for dense Map and Block expression with direct access.
This base class provides the const lowlevel accessors (e.g. coeff, coeffRef) of dense Map and Block objects with direct access. Typical users do not have to directly deal with this class.
This class can be extended by through the macro plugin EIGEN_MAPBASE_PLUGIN
. See customizing Eigen for details.
The Derived
class has to provide the following two methods describing the memory layout:
Public Member Functions  
const Scalar &  coeff (Index index) const 
const Scalar &  coeff (Index rowId, Index colId) const 
const Scalar &  coeffRef (Index index) const 
const Scalar &  coeffRef (Index rowId, Index colId) const 
Index  cols () const 
const Scalar *  data () const 
Index  rows () const 

inline 
This is an overloaded version of DenseCoeffsBase<Derived,ReadOnlyAccessors>::coeff(Index) const provided to bypass the creation of an evaluator of the expression, thus saving compilation efforts.
See DenseCoeffsBase<Derived,ReadOnlyAccessors>::coeff(Index) const for details.

inline 
This is an overloaded version of DenseCoeffsBase<Derived,ReadOnlyAccessors>::coeff(Index,Index) const provided to bypass the creation of an evaluator of the expression, thus saving compilation efforts.
See DenseCoeffsBase<Derived,ReadOnlyAccessors>::coeff(Index) const for details.

inline 
This is the const version of coeffRef(Index) which is thus synonym of coeff(Index). It is provided for convenience.

inline 
This is the const version of coeffRef(Index,Index) which is thus synonym of coeff(Index,Index). It is provided for convenience.

inline 

inline 
Returns a pointer to the first coefficient of the matrix or vector.

inline 